Direct observation of HO2/O2- free radicals generated in water by a high-linear energy transfer pulsed heavy-ion beam.
The formation and decay of HO2/O2- radical from the radiolysis of water by heavy 36S16+ ions (2.7 GeV) have been observed by time-resolved absorption spectroscopy at 260 nm. The experiment was performed at the Grand Accélérateur National d'Ions Lourds (Caen, France). In deaerated water, for a linear energy transfer (LET) of 250 eV/nm, the yield of HO2/O2- is (6 +/- 2) x 10(-9) mol J-1. In aerated solution, an additional formation of O2- is observed due to the reaction of hydrogen atom and e(aq)- with oxygen. The experimental G values are compared to those obtained with light ions for the same LET. The importance of the initial velocity is discussed briefly.
Baldacchino
G
G
DSM/DRECAM/SCM URA331 CNRS, CEA/Saclay, Gif sur Yvette, France.
Le Parc
D
D
Hickel
B
B
Gardès-Albert
M
M
Abedinzadeh
Z
Z
Jore
D
D
Deycard
S
S
Bouffard
S
S
Mouton
V
V
Balanzat
E
E
D004307:Dose-Response Relationship, Radiation; D005609:Free Radicals; D006863:Hydrogen-Ion Concentration; D018499:Linear Energy Transfer; D010315:Particle Accelerators; D011830:Radiation Effects; D011854:Radiochemistry; D013455:Sulfur; D013481:Superoxides / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
D005609:Free Radicals; D014867:Water; D013481:Superoxides; D013455:Sulfur